Meter All The Phases: Three Phase Energy Meter With OpenWrt

Keeping track your overall electricity usage is a good thing, and it’s even better if you know where all the kilowatt-hours are going. [Anurag Chugh’s] house has the three phases coming from the electrical distribution box tidily organized: One for the lighting and fans, one for household appliances, and one for the hot water supply. To monitor and analyze the electrical fingerprint of his house, [Anurag] installed a 3 phase energy meter and hooked it up to the internet.

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SSD hard drives tank laptop battery life

Tom’s Hardware has been running some tests to challenge the common assumption that SSD hard drives use power more efficiently than magnetic plate drives. Their results were quite definitive: not only are they not as energy efficient, SSDs actually use more power than conventional hard drives.

What they found is that most plate drives are at peak consumption (up to 4W) when accessing files fragmented across the media, which causes the actuator to move back and forth across the media several times. However, this is almost never sustained for extended periods of time; the actuator usually doesn’t move much when reading unfragmented data, and most plate drives are also capable of going idle when they are not in use.

Most SSDs on the other hand, only have two states: on and off. This means that when they are on, they are always at peak energy consumption. Though this number hovers around 2W for most of the SSDs they tested, over prolonged periods this can mean a great deal more power consumption than is immediately apparent, which can have short and long term effects on the battery life of a laptop. See the Tom’s Hardware article for benchmarks of specific products and more in-depth data.